JPH0229601B2 - SANSOFUKAKI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [a] Industrial Application Field The present invention relates to a device for stably and efficiently obtaining oxygen-rich air from the atmosphere, and particularly relates to an oxygen enricher suitable for medical use. . BACKGROUND OF THE INVENTION In recent years, many patients are suffering from diseases of the respiratory system such as asthma, emphysema, and chronic bronchitis, and oxygen inhalation is one of the most effective treatments for these diseases. Most current oxygen sources for this oxygen inhalation method include supplying pure oxygen obtained by cryogenic separation into cylinders, or directly evaporating liquefied oxygen and supplying it through piping. However, it requires monitoring for oxygen exhaustion, the complexity and severity of fire control due to high-pressure pure oxygen gas, and the strict management of handling high-pressure gas cylinders, making replacing and transporting cylinders complicated. This method is particularly difficult to use in general homes because piping requires complicated equipment and routes and high installation costs. On the other hand, oxygen enrichers that separate and concentrate atmospheric oxygen in close proximity to patients are attracting attention as a simple oxygen supply source. This type of oxygen enricher uses an adsorption separation method using an adsorbent such as zeolite, which adsorbs nitrogen more selectively than oxygen, and a selective permeation membrane, which allows oxygen to permeate at a higher rate than nitrogen. There are two main types of membrane separation methods. The present invention improves the noise that is most problematic in the oxygen enricher as described above, especially when it is used near a patient. b Prior art In both the adsorption separation method and the membrane separation method, the above-mentioned oxygen enricher uses the power of an electric motor to drive the pump, and in the adsorption separation method, the atmospheric air is 1 to 3 kg/cm ² G.
In the membrane separation method, the oxygen-rich gas that has passed through the selectively permeable membrane is maintained in a vacuum state of 100 to 300 Torr to obtain a predetermined oxygen concentration. It's on. In order to continuously obtain air enriched with oxygen components (hereinafter referred to as enriched air), the adsorption separation method requires air to be adsorbed and desorbed by the adsorbent, so the operating pressure is repeatedly increased and/or depressurized. This is the so-called pressure-swing system, and the compressor makes a lot of noise, which repeatedly increases and decreases, causing pain to the user, especially the sick. In the membrane separation method, the generated enriched air is only evacuated and the pressure (degree of vacuum) is also constant, so the noise generated by the vacuum pump is considerably lower than that in the adsorption separation method. When the ambient noise level is low, it can be painful for the patient or people living in the vicinity, especially when sleeping. The technology of oxygen enrichers to date has focused on improving the properties of enriched air or making the oxygen enricher more compact, and it has not been possible to deeply consider noise countermeasures from the user's perspective. . In an oxygen enricher, the pump means is driven by the power of the electric motor, so the electric motor is cooled and the gas is compressed (in the adsorption separation method, the atmosphere is transferred, and in the membrane separation method, the enriched air is transferred from vacuum to atmospheric pressure). It is an essential requirement for the stable and efficient operation of the oxygen enricher to prevent as much as possible the temperature rise of the pump itself, which occurs due to the compression of the oxygen up to the maximum temperature. Therefore, a measure is generally taken in which an amount of air several to several ten times larger than the enriched air is brought into contact with the electric motor and pump via a cooling fan to cool them. For this reason, the oxygen enricher is provided with a large-area opening on its outer wall for air to flow in and out, and a flow path with a large space inside, as a passage for cooling air. On the other hand, the pump, electric motor, and cooling fan are the main sources of noise in the oxygen enricher, and in addition, in the adsorption separation method, when regenerating the adsorbent with a pressure swing, the air rich in nitrogen adsorbed by the adsorbent is depressurized. The sound emitted when the gas is released into the atmosphere is instantaneous, but it is relatively loud. The easiest and surest way to keep noise levels low is to install the noise source in a closed space, but as is clear from the above explanation, it is best to install air passages to cool each part. It is difficult to adopt the above measures due to the need to secure the required amount. c. Purpose of the Invention The present invention has been made by intensively researching the above-mentioned points, and has particularly focused on the distance through which cooling air passes from the noise source to the opening provided in the outer wall of the oxygen enricher, and the wall vibrations that occur on the peripheral wall around the noise source. The object of this invention is to provide an oxygen enricher with a low noise level, particularly an oxygen enricher suitable for medical use. d Structure of the Invention In an oxygen enricher for obtaining oxygen-enriched air from the atmosphere using at least one pump means driven by the power of an electric motor, an air intake provided on a surface forming an outer shell of the enricher is provided. an inlet and an atmospheric outlet;
A chamber structure that houses the electric motor and the pump means built in the enricher, and an air inflow opening into the chamber structure provided on a surface forming the chamber structure, and an air outflow from the chamber structure. at least one pump housing having an opening; an atmospheric inflow passage restricting the flow of atmospheric air from the atmospheric air intake to the atmospheric inlet opening; an atmospheric exhaust passageway that restricts the flow, and the length of the atmospheric inflow passageway and the length of the atmospheric exhaust passageway are each the minimum length between opposite ends of the surface constituting the enricher outer shell. As described above, the oxygen enricher is characterized in that each of the atmospheric inflow passage and the atmospheric discharge passage is bent three times or more, and furthermore, the oxygen enricher is provided with an outer surface on the front side of the oxygen enricher. The oxygen enricher is characterized by having a space at least partially inside the shell. The oxygen enricher according to the present invention obtains so-called oxygen-enriched air having a higher oxygen concentration than the atmosphere, and either adsorption separation or membrane separation may be used as a means for increasing the oxygen concentration. Further, the oxygen enricher incorporates at least one pump means, such as a vacuum pump or a compressor, driven by the power of an electric motor. Such a pump means is housed in a pump storage chamber forming a part of the enricher, but the storage chamber can accommodate one or more pump means, and the storage chamber usually has one or more pump means. It is preferable that the number is 2, but it may be 2 or more. The blower used in the enricher may be placed in the middle of the atmospheric passage, but if the generated noise is large, it may be built in the storage chamber. The atmosphere flowing through the oxygen enricher of the present invention does not mean air flowing through a pump connected to the pump means, but air flowing through a relatively large passage such as a duct. Although the oxygen enricher according to the present invention will be explained in more detail, the drawings merely show one embodiment of the present invention, and the present invention is not limited by the drawings. FIG. 1 shows a schematic structure of a membrane separation method oxygen enricher (hereinafter abbreviated as membrane type enricher) to which the present invention is applied. In a membrane type enricher, by sweeping a large amount of air to one side of the separation membrane and keeping the other side at a low level, oxygen is concentrated (enriched) on the low pressure side due to the gas selective permeability of the separation membrane. A practical configuration in which many such separation membranes are stacked together is called a module. In the figure, a housing 1 has an air passage formed by a large number of wall members, and air taken in from outside the housing through an air intake port 2 is passed through a blower 3 and a membrane module 4.
The air is fed into the storage chamber through the air inflow passage 5 containing the air, and through the air inflow opening 8 of the storage chamber 7 in which the vacuum pump 6 is installed. Inside the storage chamber 7 , heat is exchanged with the pump section and motor of the vacuum pump 6 , and the heated atmosphere is discharged from the storage chamber 7 through the atmosphere outlet opening 9 , passes through the atmosphere exhaust passage 10 , and enters the atmosphere exhaust port 11 .
It is discharged outside the casing. Among the above atmospheric passages, the part with the highest noise level is the pump storage chamber 7, and the key technical point is how to suppress the noise generated from this storage chamber 7 or prevent it from propagating outside the housing. Since the noise from the blower is small, it will be ignored here and considered as part of the air inflow passage as described above. In order to reduce the noise level in the storage room 7,
Use a low-noise vacuum pump, or
Measures such as installing sound-absorbing material inside the storage chamber 7 have been taken, but such measures alone cannot satisfy the currently required noise level of medical oxygen enrichers, and it is difficult to suppress the propagation of sound from the storage chamber 7. This requires some ingenuity. As a means of achieving this, it is possible to install sound insulating materials in addition to sound absorbing materials inside the storage chamber 7, which can considerably suppress the propagation of sound from the storage chamber 7 through the walls, but the air required to cool the vacuum pump is Due to the large volume, there is a limit to reducing the area of the air inflow opening 8 and the air outflow opening 9, and the leakage of sound from these parts is at a considerably high level, and how to suppress this noise is critical to the entire enrichment device. It affects the height of the noise level. In a membrane type enricher, as shown in Fig. 1, the membrane module 4 etc. are installed in the air inflow path, and the path can also be bent considerably, so that leakage from the air inflow opening 8 is prevented. The noise is considerably attenuated until it reaches the atmosphere intake port 2, and the noise leaking from the atmosphere outflow opening 9 becomes dominant. As a result of intensive studies to suppress the leakage noise to a low level, the inventors of the present invention found that the opening 8 provided in the storage chamber 7
or the passage length from 9 to the opening 2 or 11 of the housing,
That is, if each of the passage lengths 2→8 and 9→11 is made larger than the minimum dimension of the enricher outer shell surface, and the number of passages is bent at least 3 times, leakage noise can be greatly attenuated. It has been found that this can be achieved, and the present invention has been achieved. Generally speaking, the longer the distance through which the atmosphere travels, the lower the noise level will be.However, in the case of noise with a mixture of various frequencies, such as from an enricher, if the distance through which the atmosphere travels is not selected carefully, it will cause resonance. There is a possibility that sound at a specific frequency will be amplified. However, it has been found that by bending the atmospheric passage an appropriate number of times, it is possible to suppress resonance as long as the passage distance is a certain length or more, and at the same time, it is possible to reduce the driving sound of various frequencies almost equally. That is, the passing distance should be at least the minimum value of the outer shell dimension of the enricher, preferably at least 1.5 times. If the passage distance is too short, low frequency sounds will not be attenuated. On the other hand, the sound absorption effect at the bends in the atmospheric passage prevents sound reflection or sound resonance, which has a great effect on noise reduction, but unnecessarily increasing the number of bends complicates the structure of the enricher. Not only does this increase the cost of the housing, but it also increases atmospheric pressure loss and increases the noise level of the blower, which is not desirable. The number of bends is preferably three or more in order to effectively reduce the noise level down to the low frequency range. Furthermore, it is more preferable to install a sound absorbing material or a sound absorbing material and a sound insulating material at the bent portion. Noise countermeasures for general equipment deal with high-frequency noise of around 4000Hz, but oxygen enrichers deal with high-frequency noise of around 100Hz.
The frequency of 2000Hz is dominant, and the above means are very effective in reducing the noise level below 500Hz. FIG. 2 shows various embodiments of atmospheric exhaust passages in membrane enrichers. In Figure 2, the left side of the drawing shows the front side (usually the operating surface) of the enricher, and the part marked with a circle in the middle of the dashed line in the figure represents the essential bending part. show. It is preferable to ignore the bending and exhaustion at the atmosphere exhaust port, as this does not result in a significant reduction in noise. FIG. 2a schematically shows the atmospheric passage in FIG. 1, and the number of bends is 3, and on the sides b, c, and d, the number of bends is 4, 3, and 4, respectively. As shown in FIG. 2c, when the space 14 is formed by the operating side housing wall member 12 and the storage chamber wall member 13, surface noise generated from the periphery of the storage chamber 7 is directly emitted to the outside of the housing. Furthermore, using the space 14 as part of the air path as shown in Figures a and b prevents storage room surface noise and increases the path length and number of bends. It is also very preferable from this point of view. As mentioned above, it is effective to install sound absorbing material at the bend in the air path shown by the dashed line in FIG. It is more preferable to install it at least 1/5 of the total length including the bent part. Adsorption type enrichers do not require a large amount of swept air like the membrane type, but because the pump temperature rises large, they ultimately require the same amount of cooling air as the membrane type. In the adsorption type, since the pump is a compressor, the generated noise is louder than the model, and the structure of the enricher itself is simple, so if the present invention is applied and the cooling air path is devised, the noise level can be significantly reduced. FIG. 3 illustrates an embodiment of the invention. Figure 3a shows an example in which the number of bends in the flow path for atmospheric air to enter and exit the pump storage chamber 7 is 3 times, b and c are 5 times and 4 times, respectively. c indicates the flow path on the outflow side. When b and c are integrated, the part where the passage parts overlap shows a state in which the flow path is divided into two in the direction perpendicular to the plane of the paper, which increases the passage length and the number of bends while simplifying the housing structure. This is an attempt to increase the number of people. e Effects of the Invention According to the present invention, it is possible to attenuate leakage noise from the oxygen enricher and provide an oxygen enricher that can operate extremely quietly. As an example, the noise reduction effect was measured for a membrane type enricher that was bent twice as shown in Figure 4, three times as shown in Figure 2c, and four times as shown in Figure 2b. The results are shown in the table below. In addition, the noise reduction effect is 15 dB to give a sense of quietness.
It is said that (A) or more. 【table】

[Brief explanation of drawings]

Fig. 1 shows a schematic structure of a membrane enricher to which the present invention is applied, Fig. 2 shows an example of an embodiment of an outflow channel, and Fig. 3 shows an embodiment of an adsorption type enricher to which the present invention is applied. An example of this embodiment is shown in FIG. 4, which shows an outflow channel of a model enricher which was bent twice in order to examine the effects of the present invention.

Claims (1)

[Scope of Claims] 1. In an oxygen enricher for obtaining oxygen-enriched air from the atmosphere using at least one pump means driven by the power of an electric motor, an oxygen enricher provided on a surface forming an outer shell of the enricher. a chamber structure for accommodating the electric motor and the pump means built in the enricher, and the air inflow into the chamber structure provided on a surface forming the chamber structure; at least one pump housing chamber having an opening and an atmospheric outflow opening from the chamber structure; an atmospheric inflow passage restricting the flow of atmospheric air from the atmospheric intake to the atmospheric inflow opening; and an atmospheric outflow opening. and an atmosphere exhaust passage that restricts the flow of atmosphere from the part to the atmosphere exhaust port,
Each of the length of the atmospheric inflow passage and the length of the atmospheric discharge passage is greater than or equal to the minimum length between opposite ends of the surface constituting the outer shell of the enricher; An oxygen enricher characterized in that each passage is bent three times or more. 2. The oxygen enricher according to claim 1, wherein the atmosphere inlet passage and/or the atmosphere discharge passage has a sound absorbing material installed on at least a part of its inner surface. 3. The oxygen enricher according to claim 2, wherein the atmosphere inlet passage and/or the atmosphere discharge passage has a sound absorbing material installed on the inner surface of 1/5 or more of the length thereof. 4. The oxygen enricher according to claim 2, wherein the atmosphere inflow passage and/or the atmosphere discharge passage has a sound absorbing material installed on the inner surface of at least one bent portion. 5. In an oxygen enricher that obtains oxygen-enriched air from the atmosphere by using at least one pump means driven by the power of an electric motor, an air intake port provided on the surface forming the outer shell of the enricher and an air A chamber structure that houses an exhaust port, the electric motor built in the enricher, and the pump means, an air inflow opening into the chamber structure provided on a surface forming the chamber structure, and the chamber structure. at least one pump housing having an atmospheric outflow opening from the atmospheric outflow opening; an atmospheric inflow passage restricting the flow of atmospheric air from the atmospheric inlet to the atmospheric inflow opening; and from the atmospheric outflow opening to the atmospheric outlet; and an atmospheric exhaust passage that restricts the flow of atmospheric air to the
Each of the length of the atmospheric inflow passage and the length of the atmospheric discharge passage is greater than or equal to the minimum length between opposite ends of the surface constituting the outer shell of the enricher; An oxygen enricher characterized in that each passage is bent three times or more, and has a space at least partially inside an outer shell on the front side of the enricher. 6. The oxygen enricher according to claim 5, wherein the space is a part of the atmosphere inflow passage and/or the atmosphere discharge passage. 7. The oxygen enricher according to any one of claims 5 and 6, wherein the atmosphere inflow passage and/or the atmosphere discharge passage has a sound absorbing material installed on at least a part of its inner surface. .